Prime Minister Shinzo Abe is considering forgoing bilateral talks with South Korean President Moon Jae-in on the sidelines of the Group of 20 summit to be held in Japan in June, government sources said Saturday.

The move underscores the deteriorating ties between the two neighbors mainly due to disputes over wartime compensation issues related to Japan’s 1910-1945 colonization of the Korean Peninsula.

It is highly unlikely that Abe can have a “constructive” dialogue with Moon, who has shown no signs of eagerness to improve chilled relations, one of the sources said.

During the G20 summit to be held for two days from June 28 in Osaka, Abe is arranging face-to-face meetings with U.S. President Donald Trump, Chinese President Xi Jinping and Russian President Vladimir Putin.

Abe and Moon last held talks in September in New York. Since then, they have not even talked on the phone, according to a senior Foreign Ministry official in Tokyo.

The two countries are in a standoff over a row stemming from a ruling by a top South Korean court last October ordering Nippon Steel and Sumitomo Metal Corp. to pay compensation for what was recognized as wartime forced labor, among other issues.